I have never used the Yankee Hill Machine Co, Inc., AR's but have seen them. You need to check out Model 1 Sales they have uppers and i know they sale YHM stuff on they upper.

"WAR IS A RACKET, I spent most of my time being a high-class muscle-man for Big Business, for Wall Street, and for the Bankers." Major-General Smedley Darlington Butler USMC Ret. 2 time Medal of Honor winner.

There's this guy who is shooting against me, in the tournament I'm in, and he's using a Yankee Hill Black Diamond Rifle. It's the first one I've ever seen. He's in 4th place right now behind me, but I bet he's going to move up in the 5.56mm 600 meter competition in the 3rd and 4th rounds tomorrow morning. I'm currently in 2nd place after the first two rounds from last week, but I see this guy as bigger competition than the guy that's in first place ahead of me. It seems to be a very fine rifle. I wish I knew more about it and if it's a good buy for you or not for that upper. Good luck to you.